1. Technical Field of the Invention
The present invention relates to a novel class of polycyclic compounds which are modulators of receptors of Peroxisome Proliferator-Activated Receptor type of subtype γ (PPAR-γ). This invention also relates to a process for the preparation thereof and to their formulation into pharmaceutical compositions suited for human or veterinary medicine, or alternatively for cosmetic compositions.
2. Description of Background and/or Related and/or Prior Art
The activity of receptors of PPAR type has been the subject of many studies. Mention may be made, as a guide, of the publication entitled “Differential Expression of Peroxisome Proliferator-Activated Receptor Subtypes During the Differentiation of Human Keratinocytes”, Michel Rivier et al., J. Invest. Dermatol., 111, 1998, pp. 1116–1121, in which are listed a large number of bibliographic references relating to receptors of PPAR type. Mention may also be made, as a guide, of the report entitled “The PPARs: From orphan receptors to Drug Discovery”, Timothy M. Willson, Peter J. Brown, Daniel D. Sternbach and Brad R. Henke, J. Med. Chem., 2000, Vol. 43, pp. 527–550.
PPAR receptors activate transcription by binding to elements of DNA sequences, known as peroxisome proliferator response elements (PPRE), in the form of a heterodimer with retinoid X receptors (known as RXRs).
Three subtypes of human PPARs have been identified and described: PPARα, PPARγ and PPARδ (or NUC1).
PPARα is mainly expressed in the liver, while PPARδ is ubiquitous.
PPARγ is the most extensively studied of the three subtypes. All prior art references suggest a critical role of PPARγ in regulating the differentiation of adipocytes, where it is greatly expressed. It also has a key role in systemic lipid homeostasis.
It has been described, in particular in WO 96/33724, that PPARγ-selective compounds, such as a prostaglandin-J2 or -D2, are potential active agents for treating obesity and diabetes.
Moreover, the assignee hereof has already described PPARγ compounds and/or the use thereof in the following patent applications. FR 98/02894 describes the use of PPARγ activator compounds in the preparation of a pharmaceutical composition, the composition being intended to treat skin disorders associated with an anomaly of epidermal cell differentiation. WO 01/02543 describes a novel class of PPARγ-modulating compounds.